Three-Dimensional (3D) scanning technologies allow real-world objects and environments to be converted into corresponding 3D virtual objects. The 3D virtual objects have many possible uses such as for 3D printing, augmented reality (AR) and virtual reality (VR) experiences, rapid prototyping, and more. Typically, a 3D virtual object may be generated by scanning the environment with one or more scanning devices, which include any number of environmental sensors capable of detecting physical features of the real-world. These physical features are translated into corresponding features of the 3D virtual object.
In some approaches to 3D scanning, a user is able to physically manipulate a scanning device, such as a mobile phone, in order to control the device pose, as well as the distance of the device from one or more real world objects and/or spaces that are the subject of a scan. The scanning device can include a camera to collect scan data including distance information about surfaces within its field as well as surface texture and color info nation. In order to receive high quality scan data, the camera should be positioned an optimal distance from the subject of a scan, which may change as different regions are being scanned. This distance may be based on the focal length of the camera. Some cameras have an adjustable focal length, such those with a zoom lens. However, it may not always be feasible to adjust focal length, such as where the camera has a fixed focal length. In these cases, the user may not be able to judge the optimal distance for scanning, which can reduce the quality of the scan.